Audio

This guide covers basic audio control (mute/volume), advanced audio control (balance, sync offset, monitoring, multi-track routing, special inputs), and real-time volume meters used for voice-activity detection.

Audio Control

Function	Description
`SetInputMute(Name, Muted)`	Mute/unmute an input
`ToggleInputMute(Name)`	Toggle mute state
`GetInputMute(Name)`	Fetch current mute state
`SetInputVolume(Name, VolumeDb)`	Set volume in decibels
`SetInputVolumeMultiplier(Name, VolumeMul)`	Set volume as multiplier (0.0 to 1.0+)
`GetInputVolume(Name)`	Fetch current volume
`AdjustInputVolume(Name, DeltaDb)`	Adjust volume relatively
`GetInputList()`	Refresh input list from OBS
`GetCachedInputs()`	Get locally cached input list

Advanced Audio Control

Function	Description
`GetInputAudioBalance(Name)`	Fetch stereo balance (async)
`SetInputAudioBalance(Name, Balance)`	Set stereo pan (0.0=left, 0.5=center, 1.0=right)
`GetInputAudioSyncOffset(Name)`	Fetch sync offset in ms (async)
`SetInputAudioSyncOffset(Name, OffsetMs)`	Set sync offset (-950 to 20000ms)
`GetInputAudioMonitorType(Name)`	Fetch monitor type (async)
`SetInputAudioMonitorType(Name, Type)`	Set monitor type
`GetInputAudioTracks(Name)`	Fetch track routing states (async)
`SetInputAudioTracks(Name, Tracks)`	Set all track states (1-6)
`SetInputAudioTrack(Name, Track, Enabled)`	Set single track state
`GetSpecialInputs()`	Fetch default audio devices
`GetCachedSpecialInputs()`	Get cached special inputs
`RefreshAllAdvancedAudioInfo()`	Fetch all advanced audio info for cached inputs

Audio balance:

0.0 = Full Left
0.5 = Center (default)
1.0 = Full Right

Sync offset:

Range: -950 to 20000 ms
Negative values = audio plays earlier (compensates for processing delay)

Monitor types (EOBSMonitorType):

Value	Description
`None`	No monitoring (default)
`MonitorOnly`	Hear in OBS but NOT in stream/recording
`MonitorAndOutput`	Hear in OBS AND in stream/recording

Audio tracks:

Tracks 1 to 6 can be independently enabled/disabled.
Used for multi-track recording (separate game/mic/Discord audio).
Configure output tracks in OBS Settings → Output → Recording.

Volume Meters & Voice Activity

Real-time per-input audio levels. This is a high-frequency event and is off by default, so opt in only when you need it.

Function / Event	Description
`SetVolumeMetersEnabled(bEnable)`	Opt into the `InputVolumeMeters` event (per-input, multi-channel levels)
`OnInputVolumeMeters`	Fires with an `FOBSInputVolumeMeter` per input, providing linear multiplier and derived dB, plus a convenience loudest-channel peak
`GetClient()->GetAudio()->GetLastVolumeMeters()`	Poll the most recent meter frame instead of binding the event
`SetInputActiveStateEventsEnabled(bEnable)` + `OnInputActiveStateChanged`	An input’s video-active state changed

For ready-made talking/idle detection built on these meters, see Voice Activity Detection.

Note: OBS reports empty levels for a muted input.

Audio / Inputs Events

OnInputMuteStateChanged(InputName, bMuted): Input mute changed
OnInputVolumeChanged(InputName, VolumeDb, VolumeMul): Volume changed
OnInputAudioBalanceChanged(InputName, InputUuid, Balance): Stereo balance changed
OnInputAudioSyncOffsetChanged(InputName, InputUuid, SyncOffsetMs): Sync offset changed
OnInputAudioTracksChanged(InputName, InputUuid, AudioTracks): Track routing changed
OnInputAudioMonitorTypeChanged(InputName, InputUuid, MonitorType): Monitor type changed
OnSpecialInputsReceived(SpecialInputs): Default audio devices fetched
OnInputSettingsChanged(InputName, InputUuid): Input settings were modified (notification only)
OnInputSettingsReceived(InputName, InputKind, Settings): Input settings data fetched (with full data)
OnInputListUpdated: Input list was refreshed
OnInputCreated(InputName, InputUuid, InputKind, UnversionedInputKind): New input created
OnInputRemoved(InputName, InputUuid): Input was removed
OnInputNameChanged(InputUuid, OldInputName, NewInputName): Input was renamed
OnInputKindListReceived(InputKinds): Available input kinds fetched

For the full catalog of events across every OBS domain, see the Events reference.